Polyvinyl acetal resin sheets containing the ethyl ether of diethylene glycol succinate



Patented Oct. 1, 194G UNITED STATES F PATENT OFFICE Henry B. Smith and Donald R. Swan, Rochester,

N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey is Drawing. Application September 14,1938,

- Serial No. 229,918

This invention-relates to plastic compositions, and more particularly to compositions comprising a polyvinyl acetal resin and a conditioning agent.

One object of this invention is to produce compositions of matter which may be made into permanently transparent, strong and flexible sheets or films of desired thinness which are. substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support for sensitive photographic coatings. Another object of our invention is to produce compositions of matter which'can be made into sheets suitable for use in laminated, shatter-proof glass. Still another object is to produce compositions which can be rolled, extruded, molded or otherwise worked intorelatively thick sheets and massive plastics. A further object is to produce compositions suitable for use in lacquers, artificial silk filaments, wrapping tissues and the like. Other objects will hereinafter appear. I

We have discovered that the ethyl ether of diethylene glycol succinate is a very useful conditioning agent for polyvinyl acetal resins. Not 5 only does it serve. as a plasticizer in the accepted sense of the term, increasing the flexibility and toughness of polyvinyl acetal resin fllmspsheets,

or other objetcs or masses containing it, but when used in amounts of about 50 or 75 or more parts per 100 parts of certain of the polyvinyl acetal resins, namely the polyvinyl acetal resins in which a predominating proportion of the acetal groups acetal groups, it has an unusual and remarkable '35 effect which we may call elasticizing." That is v to say, a sheet of polyvinyl formaldehyde or acetaldehydeacetal' resin containing about 50 or 75 or more parts of the ethyl ether of diethylene gylcol succinate per 100 parts of resin possesses the property which, in the rubber industry, is known as "nerve: namely, the property of stretching to a considerable extent whentension is exerted upon it, and returning to its original dimensions when the tension is released. This property renders such sheets, which we shall call rubbery" sheetsparticularIy useful in the manufacture of shatter-proof glass.

For the manufacture of cast films or sheets, the polyvinyl acetal resin andthe' ethyl ether of diethylene glycol succinate may be dissolved in a suitable solvent or solvent mixture, such, for instance, as acetone, methanol, acetone-methanol mixtures, ethylene chloride-methanol mixtures,

etc., about 300m 500 or more parts of the solvent or solvent mixture being used per 100 parts of the (o1. coo -3e) resin. From about 1 to 100 or more parts of the ethyl ether of diethylene glycol succinate per 100 parts of resinmay be employed, depending upon the nature of the resin and the purpose for which the sheets are to be used; Suitable proportions of the'ethyl ether of diethylene glycol succinate for any resin and any purpose'may be readily determined by experiment. For the manufacture of sheets suitable for photographic film base, from 1 to 10 parts of theethyl ether of diethylene glycol succinate per 100 parts of resin is suitable. The resin solution is cast as a sheet, the solvent evaporated, and the sheet stripped from the casting surface.

Sheets for use 'in laminated glass may be formed by casting, or may be made without the use of volatile solvent by extrusion, for example in the manner set forth in application Serial No. 147,934 of John S. Kimble and Ernest C. Blackard, filed June 12,1937. For instance, 50 to or more parts of the ethyl ether of diethylene glycol succinate. and 190 parts of a polyvinyl formaldehyde or acetaldehyde acetal resin may be mixed in a suitable, jacketed mixer at a low temperature, for example 10 0., and the mixture 35 may then be worked on hot rolls, in the manner described in U. S. Patent 2,048,686 of F. R. Conklln, until complete homogenization has taken place. The mass thus produced may 'then be extruded through an annular die, and the tube so formed slit to form a sheet. When the resin used is a polyvinyl formaldehyde acetal resin, it will usually be found necessary to use 75 or more parts of the ethyl ether of diethylene glycol succinate per parts of resin. v p The polyvinyl acetal resins can be prepared by reacting polyvinyl alcohol with an aldehyde in the presence of an acetal condensation catalyst, e. g., a mineral acid. These resins can also be prepared by simultaneously de-esterifyinga poly-' vinyl aliphatic ester and reacting the de-ester ,iiication product with an aldehyde in the presence of a de-esterifying catalyst and acetal condensation catalyst. Mineral acids are catalysts for both de-esteriflcation and acetal formation. Among the polyvinyl acetal resins withwhich the ethyl ether of diethylene glycol succinate is useful may be mentioned, as illustrative examples" the polyvinyl formaldehyde acetal resins,'the polyvinyl acetaldehyde acetal resins, the polyvinyl 50 formaldehyde acetaldehyde mixed acetal resins, the polyvinyl butyraldehyde acetal resins, and the polyvinyl 'butyraldehyde acetaldehyde mixed acetal resins.

Examples of the preparation of polyvinyl form- 7/ aldehyde acetal resins may be found in 11.8. Patent 1,955,068, Examples 1, 4 and 5; in ,U. S.

Patent 2,036,092, Examples 1, 2, 3, 7 and 8; in British Patent 454,691, Examples 1, 2, 3, 4, 5, 6

and 7; in British Patent 404,279, Example 3; and in British Patent 436,072, Examples 1, 2, 3, 4, 5,

of acetic acid. To this solution were added 56 grams of hydroxylamine hydrochloride, for stabilizing the resin, 5.25 lbs. of trioxymethylene, and 6.25 lbs. of 35% HCl. The reaction mixture was allowed to stand for 5 days 40 C., after which it was diluted with acetic acid. The resin was precipitated by pouring into cold water, washed, and dried. Analysis showed the resin to have an acetate group content equivalent to 10.6% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 7.1% by weight of polyvinyl alcohol. The stabilization of polyvinyl acetal resins by hydroxylamine is claimed in the application of Joseph B. Hale, Serial No. 149,916, filed June 23, 1937.

70 lbs. of polyvinyl acetate, the viscosity of whose molar solution in benzene was 45 centipoises, was dissolved in a mixture of 336 lbs. of glacial acetic acid and 224 lbs. ,of water. After solution was effected, there were added a solution of 318 grams of sodium nitrite in 500 cc. of water, for stabilizingthe resin, 15.2 lbs. of trioxymethylene and 17.5 lbs. of 35% HCl. The reaction mixture was allowed to stand for 5days at 40 0.,

whereupon 5 lbs. additional 35% 1101 was added and the reaction continued for 6 days longer: a total of 11 days at 40 C. The reaction mixture was then diluted with a mixture of acetic acid and ethyl alc'ohol, and the resin was precipitated by pouring into cold water, washed, and dried. Analysis showed the resin to have an acetate group content equivalent to 10.7% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 11.2% by weight of polyvinyl al-.

cohol. The stabilization 'of polyvinyl acetal resins by nitrous acid is claimed in the application of Charles R. Fordyce and Martti Salo, Serial No. 159,193, filed August 14, 1937.

Examples of the preparation of polyvinyl acetaldehyde acetal resins may be found in U. 8. Patent 2,044,730, Example 1; U. 8. Patent 1,955,068, Example 2; U. S. I atent 2,036,092, Examples 4, 5 and 6; British Patent 466,598,

' Examples 1, 2, 3, 4 and 7; British Patent 404,279,

Examples 1, 2, 4, 5, 6, 7 and 8; U. S. Patent 1,990,399; and French Patent 808,578, Examples 1, 2 and 3.

Additional examples of the preparation of polyvinyl acetaldehyde 'acetal resins are as follows: 100 lbs. of polyvinyl acetate, the viscosity of whose molar solution in benzene was 45 centipoises, was dissolved in 300 lbs. of 95% ethyl al-,

cohol. .To this solution were added 30 lbs. of paraldehyde and-25 lbs. of 35% I101. The reaction mixture was allowed to stand for 4 days atthe resin to have in acetate group content equiva lent to 2.1% by weight of polyvinyl acetate and f a hyd'roxyl-group content equivalent to 12.9% by weight of'polyvinyl alcohol.

25 lbs. of polyvinyl acetate, the viscosity of I at a temperature of 40 C. for 144 hours.

whose molar solution in benzene was 45 centipoises, was dissolved in 75 lbs. of 9.5% ethyl alcohol. To this solution was added 8 lbs. of paraldehyde and a solution of 3 lbs. 12 07s. of sulfuric weight of polyvinyl alcohol.

.50 lbs. of polyvinyl acetate the viscosity of whose molar solution in benzene was 45 centipoises, was dissolved in a mixture composed of 50 lbs. of 95% ethyl alcohol and lbs. of ethyl acetate. To this solution was added 19.2 lbs. of paraldehyde. Then a catalystconsisting of 5 lbs.

.of sulfuric acid diluted with 5 lbs. of water was added. After thorough mixing, the reaction was allowed to proceed at 40 C. for 8 days. The reaction mixture was then diluted with acetone,

and the resin precipitated by pouring into cold water, washed and dried. Analysis showed the resin to have an acetate group content equivalent to 3.3% of polyvinyl acetate and a hydroxyl group content equivalent to 6.5%% of polyvinyl alcohol.

Examples 'of the preparation of polyvinyl formaldehyde acetaldehyde mixed acetal resins may be found in British Patent 430,136, Examples 1, 2, 3, 4, 5 and 6; British Patent 445,565, Example 2; British Patent' 465,873, Examples 1, 2, 3, 4, 5 and 6; French Patent 808,586, Examples 1, 2, 3, 4, 5, 6, 12, 13, 14, 15, 16, 1'7, 18 and 19.

Additional examples of the preparation of polyvinyl formaldehyde acetaldehyde mixed acetal resins are given in the application of Ralph H. Talbot Serial No. 85,960, filed June 18, 1936, as'follows: 1

' Example 1 1 parts (1.16 moi. calculated as monomeric vinvyl acetate) of a polyvinyl acetate (45 centipoises), 100 parts of ethyl alcohol, parts of ethyl acetate, 34 parts (.77 mol. as monomeric acetaldehyde) of paracetaldehyde and 5.8 parts (.196 mol. as monomeric formaldehyde) of paraformaldehyde were placed in an enamelled vessel and brought into solution by stirring. When solution was complete, 10 parts of sulfuric acid (sp. g. 1.84) in 10 parts of water were added, and the mixture stirred. The mixture was maintained The contents of the vessel were then diluted with about two and a half volumes of acetone, and the mixture precipitated into water. The precipitated resin was washed free from impurities by repeated changes of cold water, and dried. The resin, when analyzed, gave'a hydroxyl group content equivalentto about 6.4 per cent by weight of polyvinyl alcohol, an'acetate groupcontent .equivalent to about 4.0 per cent by weight of polyvinyl acetate, a formaldehyde acetal group content equivalent to about 15.9 per cent by.

weight of polyvinyl formaldehyde acetal and an acetaldehyde acetal group content equivalent to about 73.9 per cent by weight of polyvinyl acetaldehyde acetal. The polyvinyl acetal portionof the resin was therefore made up of about 19.7 per cent by moles of polyvinyl formaldehydeacetal and about 80.3 per cent by moles-of polyvinyl acetaldehyde acetal. The resin was soluble in acetone to an extent which permitted coating a film orsheet from the resin. I

"Example 2 "50 parts (.58 mol. as monomer) of polyvinyl acetate centipoises), parts of ethyl alcohol, parts of ethyl acetate, 17 parts (.385. mol. as monomer) of paracetaldehyde, 2.9 parts (.098 mol. as monomer) of paraformaldehyde, 5 parts of sulfuric acid and 5 parts of water were treated as in Example 1 for 161 hours. The well washed and dried resin gave upon analysis a hydroxyl group content equivalent to about 9.6% by weight of polyvinyl alcohol, an acetate group content equivalent to about 4.1% by weight of polyvinyl acetate, a formaldehyde acetal group content equivalent to about 13.9 per cent by weight of polyvinyl formaldehyde acetal, and an acetaldehyde acetal group content equivalent to about 69.9 percent of polyvinyl acetaldehyde acetal. The polyvinyl acetal portion of the resin was therefore made up of about 18.5 per cent by moles which permitted coating a film or sheet from the resin.

Example 3 1300 parts (15.1 mol. as monomer) of a polyvinyl acetate (45 centipoises) 1700 parts of ethyl acetate, 2250 parts of ethyl alcohol and 48 parts (1.57 mol. as monomer) of paraformaldehyde (trioxymethylene) were placed in a vessel equipped with a reflux condenser and a means of agitation, and the contents brought to a temperature of about 70 C. by means of steam heating. 182.25 parts of sulfuric acid (sp. g. 1.84) dissolved in 51.5 parts of water were added, and the whole was heated at about 70 C. for about five hours, agitating throughout. At this point, 266.4 parts (6.05 mol. as monomer) of paracetaldehyde were added and heating at about 70 C. with agitation was continued for a further period of twenty hours. The contents of the reaction vessel were neutralized with ammonium hydroxide and diluted with water precipitating the resin as a. cake. The cake was cut into small pieces and repeatedly washed with hot water until the resin was free from solvents, salts and other impurities. The

Patent 466,598,

resin, upon analysis, showed a hydroxyl group content equivalent to about 10.1 per cent by I weight of polyvinyl alcohol, an acetate group content equivalent to about 3.2, per cent by weight of polyvinyl acetate, the remainder of the weight of the resin being polyvinyl acetal. The polyvinyl acetal portion of the resin was made up of about 80 per cent by moles of polyvinyl acetaldehyde acetal and about 20 per cent by moles of polyvinyl formaldehyde acetal. The resin was not quite soluble in acetone, but could be made to dissolve by admixing small amounts of other solvents, such as alcohols, with the acetone.

Examples of the preparation of polyvinyl butyraldehyde acetal resinsmay be found in U. S. Patent 2,044,730, Examples 2, 5 and 6; British Example 5; French Patent 813,303, Example 1; French Patent 813,514, Examples' 1, 2, 3 and 4; and British Patent 459,878, Examples 1, 2, 5, 6, 7, 8, 9 and 10.

An example of the preparation of a polyvinyl butyraldehyde acetaldehyde mixed acetal resin 'be secured by Letters Patent of the United States parts of a polyvinyl acetal resin in which a predominating proportion of .the acetal groups are selected from the group consisting of formaldehyde acetal groups and acetaldehyde acetal groups, and at least 50 parts, approximately, of the ethyl ether of diethylene glycol succinate as an elasticizer therefor.

2. A transparent, rubbery sheet comprising parts of a. polyvinyl acetaldehyde acetal resin and at least 50 parts, approximately, of the ethyl ether of diethylene glycol succinate as an'elasticizer therefor.

3. A transparent, rubbery sheet comprising 100 parts of a polyvinyl formaldehyde acetal resin and atleast 75 parts, approximately, of the ethyl ether of diethylene glycol succinate as an elasticizer therefor.

HENRY B. SMITH.

DONALD R. SWAN.

1. A transparent, rubbery sheet comprising 100 

